The principle diagram is a drawing composed of electrical symbols to analyze the principle of circuit. It has an indispensable role in product debugging, maintenance, and improvement. Principle diagram reversing and positive design is the opposite. The positive design is first designated by the principle diagram, and then the PCB design is performed according to the schematic diagram. The schematic diagram is convenient to analyze the product and assist the later product prototype to debug production or improve the upgrade.

　　In the process of product reverse technology research and imitation development, the production of the BOM list and the position diagram of the patch, the production of the coordinates of the component of the SMT patch machine are all later model welding, patch processing, and complete prototype design and assembly production. Link.

　　BOM (Material List) is the basis for the purchase of device materials, which records the various components, modules and other special materials required for the product composition. The most important thing for the production of the BOM list is that the various parameter measurement values of the meta device are accurate, because if the devices parameter is wrong, it may affect the judgment of the device and the accuracy of the material procurement, and may even lead to the failure of the project development.